More and more mobile terminals are sold in an operator customization mode, wherein a network locking function is one of important customization demands. Only one or more SIM cards or Universal Subscriber Identity Module (SIM) cards allowed to be used by an operator customizing a mobile terminal having the network locking function can be adopted on this type of mobile terminal, and SIM/USIM cards of other operators can not be normally used after being inserted into this type of mobile terminal. In order to facilitate descriptions, SIM/USIM cards are collectively, below, referred to as SIM cards in the present disclosure. The network locking function may guarantee that a user is only served by a specific operator and ensure benefits of the operator.
A common network locking method includes: processing network locking parameters by a certain encryption method and then storing the network locking parameters in a non-volatile data area of a mobile terminal; every time the mobile terminal is started, reading network locking parameters from a SIM card and relevant information, and comparing the network locking parameters and the relevant information with the network locking parameters stored in the non-volatile data area; if they are matched, allowing the mobile terminal to further read International Mobile Subscriber Identification Number (IMSI) information about the SIM card, and initializing the SIM card; otherwise, prohibiting the mobile terminal from reading the IMSI information about the SIM card to terminate an initialization flow of the mobile terminal so as to realize network locking.
The traditional art has the defects that: many crack organizations can obtain and modify network locking parameters in a mobile terminal so as to crack this network locking method, thereby damaging benefits of operators.